Bleachers have long been used to seat a multitude of people at sport events and other public performances where a large number of people are gathered. The bleachers may be used indoors as in school gymnasiums or outdoors. Especially where bleachers are used indoors they take up much valuable space and it is known to provide bleachers of the type having movable sections so that when the bleachers are not in use the sections may be moved into each other, enabling the sections to occupy a minimum of space when they are stored, the sections being extendable into position for use when they are again needed.
Guard rails are needed for purposes of safety in the case of the compactable bleacher sections just as they were in the case of permanent seat installations, but special problems arose in making the guard rail structures collapsible along with the seating sections.
One type of solution to such problems is to provide telescoping guard rails which allow the guard rails to decrease in length as the bleacher seats are compacted into each other. This is illustrated in my prior U.S. Pat. Nos. 3,401,918, 3,995,832 and 4,006,564, also in the Hartman U.S. Pat. No. 4,030,255. Other U.S. Pat. Nos. of lesser pertinency are Ryden 2,757,002; Rubenstein 2,225,889; and Schroer 2,834,621.
While the provision of telescoping rails is a substantial improvement in the art, these have some disadvantages in that they require precision in their manufacture and there are limits as to how much the rails can reasonably be expanded and shortened in length.
Accordingly, I have set about to discover ways and means by which a simplified seating and guard rail structure can be provided, preferably utilizing one piece guard rail units, while still permitting the seating sections and the guard rail units to be expanded or compacted. More specifically, it was desired to provide means for moving the guard rail units to upright position and maintaining them in such position while the seating sections are being expanded, and means for moving the guard rail units into compact position for storage while the sections are being compacted. Further, it was desired that such a means be automatically operated as the seating sections are being expanded or compacted.